It is known to provide a basic printing system having two printing stations with blanket-to-blanket construction, and to combine with such a basic system an expansion or auxiliary system. The basic and the auxiliary system each can include printing stations which can be combined with each other, or severed along a predetermined severing line. Usually, the expansion system is located above the basic printing system or printing station.
Modular printing systems, particularly for newspaper printing of intermediate to large numbers of editions, are known which are constructed generally in a bridge-type arrangement, also known as a U shape arrangement, and which include a blanket-to-blanket station. The U printing system has two printing stations which each include a damper and an inker in engagement with a plate cylinder. The plate cylinder, in turn, is in engagement with a blanket cylinder. The two printing stations are so associated with respect to each other that a paper web on which the printing is to be done is interposed between the two blanket cylinders, so that the blanket cylinders, mutually, form impression cylinders.
By modullar retrofitting, an additional printing station can expand the U-shaped basic printing system to form a Y system which permits 2/1 or, respectively, 1/2 printing, that is, two printing subject matters on the prime side and one on the verso side, or the reverse thereof. A combination of such U printing systems and Y printing systems permits expansion of the overall printing press. For example, by placing two U basic systems next to each other or above each other, it is possible to obtain dual perfecting printing, that is, 2/2 printing. This arrangement has the advantage that only standard printing stations or components, which are frequently already available, are needed to form the overall system. There is a disadvantage, however, in that a serial placement of U printing systems for 2/2 printing is spaceconsuming, and it is not possible to retrofit a Y printing station for 2/2 printing without substantial modification and expense. Thus, flexibility for later expansion of a basic system is limited in such an arrangement.
German Patent Disclosure Document DE-OS 32 20 542 illustrates a printing system of the type to which the present invention relates in which an auxiliary or expansion system is formed of two further printing stations, one of which is associated directly with one of the blanket cylinders of the basic station, and two printing stations of the second unit have a central impression cylinder associated therewith. The basic station can, initially, be formed by a Y printing system and, after amplification by the expansion system, can be expanded to permit 4/1 printing. This arrangement has the advantage of a modular construction. The possibility of expanding the Y printing station, for 2/2 perfecting printing, however, is not provided.